N-Day: A known threat, still overlooked

N-Day vulnerabilities are security flaws that are already publicly known and for which patches often exist but despite that, attacks continue to occur because organisations fail to update systems in time. This makes N-Day threats more dangerous than they appear everything is known, yet nothing is done.

Why it’s relevant to maritime and energy sectors:

Many vessels and offshore platforms operate using a diverse mix of systems, often from different vendors, and combine both legacy and modern technologies. In such environments, applying patches can be technically or logistically challenging. These delays create critical windows of exposure.

Examples from the field:

• A vessel runs an outdated operating system with a known vulnerability that has been patched for over a year
• A platform postpones a firewall firmware update to avoid connection loss, the flaw is exploited before patching
• A shoreside IT system linked to a maritime network is compromised through a known remote access vulnerability

How to protect against it:

• Monitor known vulnerability databases (e.g., CVE Common Vulnerabilities and Exposures) and routinely compare findings against your own infrastructure
• Establish structured patch management processes aligned with operational windows, using Marlink Remote IT Management services
• Develop risk mitigation plans for situations where immediate patching isn’t possible such as enhanced access controls and network segmentation

N-Day vulnerabilities remind us that cyber security is not just about technology it’s about discipline. Awareness without action doesn’t protect your systems it exposes them

Discover all the articles part of  the series "It’s a jungle out there: Navigating the digital danger zone" here.